Comparing two strings, ignoring case in C#

c# string comparison equals
pwmusic picture pwmusic · Jun 16, 2011 · Viewed 408.4k times · Source

Which of the following two is more efficient? (Or maybe is there a third option that's better still?)

string val = "AStringValue";

if (val.Equals("astringvalue", StringComparison.InvariantCultureIgnoreCase))

OR

if (val.ToLowerCase() == "astringvalue")

?

Answer

Sven picture Sven · Jun 16, 2011

If you're looking for efficiency, use this:

string.Equals(val, "astringvalue", StringComparison.OrdinalIgnoreCase)

Ordinal comparisons can be significantly faster than culture-aware comparisons.

ToLowerCase can be the better option if you're doing a lot of comparisons against the same string, however.

As with any performance optimization: measure it, then decide!

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